Outside Airflow Circulation to Cool Condenser for Integrated Transport Refrigeration Unit

ABSTRACT

A refrigeration unit includes an external housing and an internal housing supported by a vehicle roof. The external housing is located primarily outside of a vehicle compartment, and the internal housing is located primarily inside of the vehicle compartment. External air enters the refrigeration unit through a first opening located between the vehicle roof and the external housing and exits through a second opening in the external housing. The external air is heated by a condenser and a compressor and exits the refrigeration unit through the second opening. A fan is located within the second opening to control the airflow through the refrigeration unit.

BACKGROUND OF THE INVENTION

The invention relates to a transport refrigeration unit including a condenser located within a vehicle. More particularly, the invention relates to an apparatus and method for providing external airflow to a transport refrigeration unit having the condenser located in the vehicle.

Conventional transport refrigeration units provide cooling inside a vehicle compartment. The conventional transport refrigeration units are typically located on a vehicle roof within a refrigeration unit housing. The transport refrigeration unit cools air that is pumped into the vehicle compartment to provide cooling.

The condenser produces heat, and vents within the refrigeration unit housing allow for external airflow to reach the refrigeration unit components to manage the heat created by the condenser during operation. The vehicle roof acts as an insulator to protect the vehicle interior from the heat produced by the condenser.

Locating the refrigeration unit housing on the vehicle roof is unsightly. It would be desirable to locate the refrigeration unit within the vehicle compartment to hide the refrigeration unit components from external view. However, heat from the condenser and other components is emptied into the vehicle compartment, counteracting with the cooled air pumped into the vehicle compartment from the refrigeration unit. Additionally, external air must be able to reach the refrigeration unit components within the vehicle to provide cooling.

Therefore, an arrangement and a method for locating refrigeration unit components in a vehicle while providing external air to the refrigeration unit components is needed.

SUMMARY OF THE INVENTION

In the present invention a vehicle roof supports a refrigeration unit. The refrigeration unit includes an external housing located primarily outside of the vehicle compartment and an internal housing located primarily inside of a vehicle compartment. External air enters the refrigeration unit through a first opening located between the vehicle roof and the external housing and exits through a second opening in the external housing. The external air is heated by a condenser and a compressor and exits the refrigeration unit through a second opening in the external housing. The heated air does not enter the vehicle compartment, allowing the refrigeration unit components to be located within the vehicle compartment without heating the vehicle compartment. A fan is located proximate to the second opening to control the airflow through the refrigeration unit.

The internal housing may assist in insulating the components of the refrigeration unit from the interior of the vehicle. The external housing and a cover located at the second opening reduce the amount of water and other external contaminants that enter the refrigeration unit. A gasket may be located between the refrigeration unit and the vehicle roof for further sealing.

The external housing, the fan, and the cover may be assembled prior to assembly on the vehicle roof. Likewise, the internal housing, the condenser, the compressor, and an evaporator may be assembled together prior to assembly with the vehicle roof providing for easier handling and removal if any maintenance is required.

These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a vapor compression system of the present invention;

FIG. 2 shows a perspective view of a refrigeration unit of the present invention;

FIG. 3 illustrates a schematic side view from within the refrigeration unit; and

FIG. 4 is a perspective view of the components within an internal housing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a vapor compression system 10, such as a refrigeration system, including a compressor 12 that compresses a fluid, such as refrigerant. From the compressor 12, the refrigerant is delivered downstream to a heat exchanger, such as a condenser 14. In the condenser 14, the refrigerant rejects heat to an external fluid medium. In the embodiment shown, the external fluid medium is air. From the condenser 14, the refrigerant travels to an expansion device 16 and is expanded to a low pressure. The refrigerant accepts heat from another fluid medium, such as air, in an evaporator 18 and then flows to the compressor 12, completing the cycle.

FIG. 2 shows a perspective view of a refrigeration unit 20 of the present invention including the vapor compression system 10. A vehicle roof 22 supports the refrigeration unit 20. The refrigeration unit 20 includes an external housing 24 and an internal housing 26. The external housing 24 is located primarily outside of the vehicle roof 22. The internal housing 26 is located primarily inside of a vehicle compartment 21 and under the vehicle roof 22, as shown. External air enters the external housing 24 through a first opening 28 located between the vehicle roof 22 and the external housing 24. As shown, the refrigeration unit 20 can include multiple first openings 28 to increase the airflow into the refrigeration unit 20. The air passes over the components of the refrigeration unit 20, such as the condenser 14 and the compressor 12 and is heated. The now heated air exits through a second opening 30 in the external housing 24. A cover 32 may be located at the second opening 30 to reduce the amount of water and other external contaminants that may enter the refrigeration unit 20 through the second opening 30. Additionally, the external housing 24 also assists in preventing water and other external contaminants from entering the refrigeration unit 20.

FIG. 3 illustrates a schematic side view of the refrigeration unit 20. External air, illustrated by arrows A, enters the refrigeration unit 20 through the first opening 28. The external air flows past the components of the refrigeration unit 20. Specifically, the air accepts heat from the refrigerant in the condenser 14 and passes over the compressor 12 prior to exiting the refrigeration unit 20 through the second opening 30. The refrigerant cooled by the condenser 14 is expanded in the expansion device 16 and flows into an evaporator 18, where the refrigerant cools air to be sent into the vehicle compartment. The outside air accepts heat from both the condenser 14 and the compressor 12, removing heat from the compressor 12 as a result of operation. The heated air exits the refrigeration unit 20 through the second opening 30 and flows outside the vehicle.

A fan 38 located proximate to the second opening 30 controls the airflow through the refrigeration unit 20. The revolutions per minute of the fan 38 may be increased or decreased to adjust the airflow through the second opening 30. A sensor 39 located within the refrigeration unit 20 measures the temperature and adjusts the fan 38 accordingly. As the sensor 39 senses a rise in the temperature of the air exiting the refrigeration unit 20, the fan 38 is adjusted to a higher speed. Likewise, when the sensor 39 senses a drop in the temperature of the air exiting the refrigeration unit 20, the fan 38 is adjusted to a lower speed.

The condenser 14 is located proximate to the first opening 28 and in the airflow path of the refrigeration unit 20. Both the condenser 14 and the compressor 12 are primarily located within the internal housing 26 under the vehicle roof 22. Additionally, the evaporator 18 may also be located within the internal housing 26, as shown in FIG. 4. However, the evaporator 18 need not be located within the airflow path through the refrigeration unit 20. The internal housing 26 assists in insulating the components of the refrigeration unit 20 from the interior of the vehicle. Gaskets 42 may be located between the refrigeration unit 20 and the vehicle roof 22 for further sealing.

The external housing 24, the cover 32, and the fan 38 may be assembled together prior to assembly on the vehicle roof 22. Likewise, the internal housing 26, the condenser 14, the compressor 12, and the evaporator 18 may be assembled together prior to assembly with the vehicle roof 22. Thus, assisting assembly onto the vehicle roof 22 and providing for easier handling and removal if any maintenance is required.

By discharging air outside of the vehicle compartment 21 to remove heat from the components, the refrigeration unit 20 can be located within the vehicle compartment 21 and under the vehicle roof 22, and is therefore less unsightly. The refrigeration unit 20 is hidden from external view, the heat generated is removed through the second opening 30 without affecting the temperature of the air in the vehicle compartment 21.

Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. 

1. A refrigeration unit for a vehicle comprising: an external housing located primarily outside a vehicle compartment; an internal housing that houses a plurality of components located primarily inside the vehicle compartment; a first opening to allow air to enter the internal housing and accept heat from the plurality of components; and a second opening to allow the air to exit the internal housing.
 2. The refrigeration unit of claim 1, wherein the external housing and a roof of the vehicle compartment define the first opening.
 3. The refrigeration unit of claim 1, wherein the second opening is defined by the external housing.
 4. The refrigeration unit of claim 1, further including a fan located proximate to the second opening to control the air from the internal housing.
 5. The refrigeration unit of claim 1, wherein the plurality of components include a compressor and a condenser of a vapor compression system, and the air accepts heat from the plurality of components.
 6. The refrigeration unit of claim 5, wherein the condenser is located proximate the first opening.
 7. The refrigeration unit of claim 1, wherein a cover is located proximate to the second opening.
 8. The refrigeration unit of claim 5, wherein the vapor compression system includes an evaporator and an expansion device.
 9. A refrigeration unit comprising: an external housing located primarily outside a structure; an internal housing that houses a plurality of components located primarily inside the structure; a first opening to allow air outside the structure to flow into the internal housing and accept heat from said plurality of components; and a second opening to allow the air to exit the internal housing.
 10. The refrigeration unit of claim 9, wherein the first opening is between the external housing and the structure.
 11. The refrigeration unit of claim 9, wherein the second opening is defined by the external housing.
 12. The refrigeration unit of claim 9, wherein the structure is a vehicle compartment.
 13. The refrigeration unit of claim 9, further including a fan located proximate to the second opening to control the air from the internal housing.
 14. The refrigeration unit of claim 9, wherein the plurality of components include a compressor and a condenser of a vapor compression system, and the air accepts heat from the plurality of components.
 15. The refrigeration unit of claim 14, wherein the condenser is located proximate the first opening.
 16. The refrigeration unit of claim 14, wherein the vapor compression system includes an evaporator and an expansion device.
 17. The refrigeration unit of claim 9, wherein a cover is located proximate to the second opening.
 18. A method of cooling a compartment comprising the steps of: flowing air through a first opening located between an external housing and a vehicle roof; directing the air over at least one component located within an internal housing located within a the compartment; heating the air with the at least one component; and flowing the air through a second opening in the external housing to exit the compartment.
 19. The method of claim 12, further comprising the step of controlling the air with a fan located adjacent the second opening.
 20. The method of claim 13, wherein the step of directing the air includes accepting heat from a condenser and a compressor. 